A gray whale can reach about 52 feet in length and weigh 36 tons. A school bus is about 36 to 39 feet long and, at most, weighs about 16 tons. So, no, a gray whale is not as big as five school buses -- a gray whale is about the length of 1.4 school buses (52 divided by 36 feet) and weighs the same as about 2.25 (36 divided by 16 tons) school buses. For more information on gray whales check out this website:

A gray whale is typically about 45-50 feet long. School buses are also typically about 45 feet long. So a gray whale is about the size of a school bus.

According to Wikipedia, if you trust that, a gray whale is about 16 meters (52 feet) long.